There is understood by card every object having a substantially planar structure defining a general plane and exhibiting any contour whatsoever in such general plane.
There is known to the person skilled in the art a card comprising electronic elements formed from a shell in which receptacles are provided intended to receive electronic elements and an outer protective layer which closes the receptacles.
There is also known a card having a symmetrical structure and formed from two substantially similar shells, each of these two shells having a structured surface serving to form receptacles intended to receive electronic elements when the two shells are assembled.
The method of manufacture of such latter card is generally as follows:
initially, each shell is formed with the help of an injection technique, for example by hot moulding. PA1 secondly, the electronic elements are placed in one of the two shells and the other shell is thereafter placed on the first, the whole matter being assembled by a hot assembly technique. PA1 B) bringing at least one electronic element onto a work surface; PA1 C) bringing a compressible positioning structure onto said work surface in a manner such that said electronic element is superposed onto said compressible positioning structure; PA1 D) bringing a binder onto said work surface; PA1 G) application of pressure onto an assembly including said electronic element, said compressible positioning structure and said binder in order to cause, on the one hand, said electronic element to penetrate at least partially into said compressible positioning structure and, on the other hand, to permit said binder to form a mass in which said electronic element is immersed; PA1 H) solidification of said mass formed by said binder at the time of said step G in a manner such that said mass rigidly binds said electronic element and said compressible positioning structure and solidifies this latter in a configuration resulting from said step G. PA1 F) applying energy serving to melt the binder at least partially.
The method of manufacture of the card described hereinbefore exhibits several drawbacks.
In particular, following hot assembly of the two shells, the electronic elements only partially fill the receptacles. This has as consequence that the card exhibits fragile zones in the places where the receptacles are situated, especially when the electronic elements incorporated in the card have relatively large dimensions. It is thus that when a winding is provided having a diameter on the order of size of the card, such a manufacturing method generates deformed zones (convexities or hollows) on the outer faces of the card this being naturally bad for the flatness of the card and for printing which can be provided on the outer surfaces of such card.
There is further known from patent document EP-0 350 179 a method of manufacture of a card consisting in placing in a mould two outer layers and an electronic assembly, then injecting a filler material in liquid form into such mould. Once hardened, such filler material forms an intermediate layer between the two outer layers.
In order to increase the rapidity of production, two chains are provided, each comprising several half-moulds coupled to one another. Both such chains are adapted to have a vertical motion and to form a mould with two corresponding half-moulds, respectively belonging to the two chains, exhibiting an opening, at least on the upper part thereof, in order to permit its filling. Above the place where the two corresponding half-moulds are assembled in order to form a mould, there is provided a nozzle permitting injection of the filling material in liquid form into the newly formed mould.
The method of manufacture of a card as described hereinbefore is complex. Additionally, for production of large quantities, such method of manufacture necessitates substantial material which renders it burdensome.
It will be further noted that the bringing in of the electronic assembly and its positioning during injection are nowhere described within the document considered here and are not evident. It is the same for the bringing of the outer layers into the half-moulds.
The card obtained by the method of manufacture described hereinbefore and such as described in patent document EP-0 350 179 is basically formed of three layers, namely an intermediate layer and two outer layers. On the interior of the intermediate layer is provided an electronic assembly formed of electronic elements, a winding arranged on its own support and an interconnection support, such interconnection support serving to couple electrically and rigidly the electronic elements and the winding.
A drawback of such card comes from the fact that the interconnection support and the support serving the winding increase the thickness of the card. Thus, it is difficult to obtain a thin card having a thickness of 0.76 mm prescribed by the ISO standard currently used for bank cards.
It will be furthermore noted that the method of manufacture proposed for such card does not assure that the interconnection support and the neighbouring outer layer are separated by a layer of filling material which is bad for good adhesion of such outer layer to the intermediate layer. Additionally, such method of manufacture does not guarantee a good positioning of the electronic assembly at the heart of the intermediate layer.
The present invention has as purpose to overcome the drawbacks described hereinbefore in proposing a method of manufacture of a card much less burdensome and well adapted to production of cards in large series, as well as proposing a solid card comprising at least one electronic element incorporated therewithin.